SOLUTION: A 20-ft diagonal brace on a bridge connects a support of the center of the bridge to a side support on the bridge. The horizontal distance that it spans is 4 ft longer than the hei

Algebra.Com
Question 548519: A 20-ft diagonal brace on a bridge connects a support of the center of the bridge to a side support on the bridge. The horizontal distance that it spans is 4 ft longer than the height that it reaches on the side of the bridge. Find the horizontal and vertical distances spanned by this brace.
Found 2 solutions by stanbon, oberobic:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
A 20-ft diagonal brace on a bridge connects a support of the center of the bridge to a side support on the bridge. The horizontal distance that it spans is 4 ft longer than the height that it reaches on the side of the bridge. Find the horizontal and vertical distances spanned by this brace.
-----
Draw the picture:
You have a right triangle with:
hypotenuse = 20 ft
height = x
base = x+4
----------------
Equation:
x^2 + (x+4)^2 = 20^2
x^2 + x^2 + 8x + 8 = 400
----
2x^2 + 8x - 392 = 0
x^2 + 4x - 196 = 0
---
I graphed the quadratic and found x = 12.14 ft (height)
base = x+4 = 16.14 ft.
---
You could use the quadratic formula.
============================
Cheers,
Stan H.
================

Answer by oberobic(2304)   (Show Source): You can put this solution on YOUR website!
x = height
x+4 = width
20 = hypotenuse
.
20^2 = x^2 + (x+4)^2
.
400 = x^2 + x^2 + 8x + 16
.
0 = 2x^2 +8x - 384
.
2x^2 +8x - 384 = 0
.
x^2 + 4x -192 = 0
.
factor
.
(x-12)(x+16) = 0
.
zeroes of x = 12 or -16
.

.
x = -16 is not applicable
.
x = 12 is the height of the span
x+4 = 16 is the width of the span
.
Check using the Pythagorean formula.
12^2 + 16^2 = 144+256 = 400
20^2 = 400
Correct.
.
Done.

RELATED QUESTIONS

A 100-ft diagonal brace on a bridge connects a support of the center of the bridge to a... (answered by mananth)
A 200-ft diagonal brace on a bridge connects a support of the center of the bridge to a... (answered by mananth)
Hi, I really need help with this please? A 15-ft diagonal brace on a bridge connects a (answered by Theo)
a 5-ft diagonal brace on a bridge connects a support of the center of the bridge to a... (answered by chessace)
9. A 150-ft diagonal brace on a bridge connects a support of the center of the bridge to... (answered by jim_thompson5910)
A 75-ft diagonal brace on a bridge connects a support of the center of the bridge to a... (answered by mananth)
I am lost on this word problem. Would it be a polynomial to be factored or the product of (answered by mananth)
Could someone help me with this word problem.I do not have a clue on how to do this. A... (answered by mananth)
I am having a nightmare with this one. Can someone please help me. A 75-ft diagonal... (answered by stanbon,Earlsdon)